Device for the cyclic rearrangement of a pile of sheets

ABSTRACT

The invention relates to a device for a cyclic rearrangement of a pile (182) of sheets having a housing (12) with a viewing window (35) and a slider member (14) that can be pulled out of the housing (12) and pushed back into the housing again parallel to the latter, and having a sheet-changing mechanism by means of which one sheet in the pile (182) is retained in the housing while the slider member (14) transports the remainder of the pile out of the housing (12), means being provided for removing the sheet remaining in the housing (12) from the housing (12) through the opening provided in the housing for the slider member (14).

The invention relates to a device for the cyclic rearrangement of a pileof sheets. A device of that general kind is described and shown in U.S.Pat. No. 4,245,417.

The known device comprises a housing having a viewing window and aslider member that can be pulled out of the housing and pushed back intothe housing again in a direction parallel to the plane defined by thewindow. A sheet-changing mechanism ensures that one sheet in the pile,for example the sheet remote from the viewing window, remains in thehousing when the slider member is pulled out and is returned to theother end of the pile as the slider member is pushed in again. Amanually-operated member is provided to disengage the sheet-changingmechanism so that the slider member then transports the entire pile outof the housing in order, for example, to enable the pile to beexchanged.

Picture-changing mechanisms that can be rendered inoperative arerelatively complicated and, when they are in their operative condition,do not allow reliable picture-changing every time.

The problem on which the invention is based is to provide asheet-changer of the type mentioned in the introduction in which theremoval of the picture remaining in the housing is effected in a simplermanner.

To solve this problem there is proposed a device for the cyclicrearrangement of a pile of sheets having a housing with a viewing windowand a slider member that can be pulled out of the housing and pushedback into the housing again parallel thereto and having a sheet-changingmechanism by means of which one sheet in the pile is retained in thehousing while the slider member transports the remainder of the pile outof the housing, means being provided to take the sheet remaining in thehousing out of the housing in the same direction as the slider member.The separate operations of removing an individual sheet and removing theremainder of the pile allow extremely simple solutions which do notdepend on inactivating the changing mechanism.

In a first preferred solution, these means comprise an "auxiliary slidermember" which can be actuated in the same direction as the slider memberwhen the slider member is out and pushes the remaining sheet "after" thepile.

In a second preferred solution, the arrangement is such that when thereis more than one sheet in the changer, the latter always "changes",thus, one picture always remains in the housing. If, however, theremainder of the pile is removed from the slider member when it has beenpulled out, then when the slider member is pushed back into the housingagain the sheet remaining in the housing is transported by the slidermember as it is pulled out again and can be removed therefrom.

The attached drawings show an example of this construction insubstantially schematic form. As regards the details of the constructionof a complete sheet-changer, a person skilled in the art can refer tothe publication mentioned in the introduction and the present inventioncan be applied to the embodiments thereof.

The attached drawings are as follows:

FIG. 1 shows a substantially diagrammatic longitudinal section through afirst embodiment, the slider member having been pushed into the housing,

FIG. 2 shows the first embodiment in a substantially diagrammaticpartial horizontal section,

FIG. 3 shows a cross-section through the separator bar from FIG. 2,

FIG. 4 shows a further embodiment in a sectional representation similarto FIG. 1, and

FIGS. 5 and 6 show a final embodiment, FIG. 5 from below, and FIG. 6 ina longitudinal section similar to FIG. 1.

In FIG. 1 the device comprises a housing 12 to the floor 218 of whichthere is secured a pressure-spring system having a first pair 24 ofspring arms and a second pair 32 of spring arms, which system presses apile 182 against a viewing window 35. The slider member is substantiallyin the form of a frame and has front wall that includes a grip part 48,from which wall two side pieces of L-shaped cross-section extend intothe housing 12 and, near their inside ends, are connected by atransverse separator bar 20. In the housing there is provided atransporter, in this case a hook-like member 22 at the end of the springarm 24. When the slider member 14 is pulled out, the downwards facingoblique surface of the separator bar presses the edges of the pile 182that are resting against it downwards, while deflecting the spring arms32, until the bottom-most sheet in the pile comes to rest behind a land68 the height of which is matched to the thickness of the sheets so thata sheet of maximum thickness lies just flush behind it. As the slidermember is pulled out further, the separator then pushes the pile 182lying on the slider-member side pieces along the upper surface of thisindividual sheet 188 which is not transported with the pile because theseparator bar 20 does not touch its edge and also because it is arrestedby the hook-like members 22 on the spring arms 24. The slider member canbe pulled out far enough for the right-hand edge of the sheet 188 inFIG. 1 to be on the left of the slider member and lifted by means notshown. If the slider member is then pushed back, this edge of the sheetslides upwards along the oblique back of the separator bar, over theseparator bar and under holding-down ribs 40, the sheet being supportedby its opposite edge on stop members 52 fixed to the housing. When theslider member has been pushed in completely, this sheet comes to rest onthe top of the pile, the right-hand end of which in FIG. 1 is pressed tothe same level by ribs 81, which level is defined by the ribs 40.

This design (as described so far), with slight modifications which areof no importance in the present invention, corresponds to the designknown from the publication mentioned at the beginning.

The above description shows that firstly there is no way or removingalso the last sheet from the housing once the remainder of the pile hasbeen removed from the slider member 14 when it is out of the housing.For that reason there is provided near the top of the separator bar 20 astep 376 the height of which is approximately equal to that of themaximum sheet thickness. During normal change operation, the edge of thelast sheet conveyed to the pile remains on this step. On the separatorbar, on either side of the step, there are arranged throw-off levermembers 378, which are pivotally mounted about axes that areperpendicular to the direction of removal of the slider member. Theselever members reach the position shown in FIG. 2 by running up againststop members 382 provided on the housing 12 as the slider member ispushed into the housing. If the slider member is then pulled out again,the lever-member arms run up against further stop members 380 on thehousing and are turned about a small angle which is, however, sufficientto throw off the edge of the sheet resting on the step. The single sheetcan then be removed, since only a sheet that has first been thrown offfrom the step can be held by the transporter 22 in front of the lowerthrough gap in the separator bar. As long, therefore, as the pileconsists of at least two sheets, the changing function is carried out;if the "pile" consists of only one sheet, this sheet is transported outof the housing by the slider member during every second change cycle.

FIG. 4 shows an alternative design of the step and control arrangement.

In the separator bar 20 there is accommodated in such a manner that itcan slide a support plate 384 which is pressed into the position shownby a spring (not shown) and only when the slider member is pulled out tothe full extent is pushed back by running up against stop members on thehousing side so far that the edge of the sheet 188 drops or, moreprecisely, is pressed by holding-down lugs 81, to below the level of theunderside of the auxiliary slider member 384. In addition, this variantis based on the same design as is the first embodiment.

FIGS. 5 and 6 show an embodiment, the change function of whichcorresponds substantially to that of the first embodiment and is forthat reason not described again here. In this case, however, theseparator bar 20 has, not a step, but a smooth slope, as in the case ofthe sheet-changers according to the state of the art. If a pile is to bereplaced, the sheet remaining in the housing 12 is pushed "after" theslider member by means of an auxiliary slider member 552 which can bemoved along a guide 554 in the bottom of the housing 12, the individualsheet sliding over the separator bar 20 and coming to rest on the pilein the slider member, which pile can, of course, also have been removedbeforehand.

I claim:
 1. Device for the cyclic rearrangement of a pile (182) ofsheets having a housing (12) with a viewing window (35) and a slidermember (14) that can be pulled out of the housing (12) and pushed backinto the housing again parallel to the latter, and having asheet-changing mechanism by means of which one sheet in the pile (182)can be retained in the housing (12) while the slider member (14)transports the remainder of the pile out of the housing (12), meansbeing provided for removing the sheet remaining in the housing (12) fromthe housing (12) through the opening in the housing provided for theslider member (14).
 2. Device according to claim 1 in which the meansare so designed and arranged that once the sheets that are transportedout of the housing by the slider member have been removed, the sheetretained in the housing can be brought out by actuating the slidermember again.
 3. Device according to claim 2 in which the slider memberhas a separator bar by means of which the sheets lying in the slidermember--with the exception of the sheet retained in the housing--aretransported, the separator defining a separating and return through gapthrough which the sheet retained in the housing passes, and theseparator having means for keeping the sheet that was the last to passthrough the return through gap away from the separating through gap oncethe slider member has been pushed into the housing.
 4. Device accordingto claim 3, in which the means for keeping the sheet away are renderedinoperative when the slider member is in the fully withdrawn position.5. Device according to claim 4, in which the means for keeping the sheetaway are arranged on the separator bar.
 6. Device according to claim 5,in which the separator bar has a stepped member for catching a sheetedge, and that sheet edge is thrown off from this stepped member whenthe slider member is in the fully withdrawn position.
 7. Deviceaccording to claim 6, in which there are provided throw-off levers thatare actuated by running up against stops on the housing side.
 8. Deviceaccording to claim 6, in which the stepped member is provided on asupport element which can be pulled back into the separator by runningup against stops on the housing side.
 9. Device according to claim 1 inwhich the means are so designed and arranged that once the sheets thatare transported out of the housing by the slider member have beenremoved the sheet retained in the housing can be transferred to thewithdrawn slider member by means of a auxiliary member.
 10. Deviceaccording to claim 9 having an auxiliary slider member that is guided inthe housing in the direction of movement of the slider member, forms theauxiliary member and acts on the sheet retained in the housing bypushing it.